Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Revenues	$ 7,053.4	$ 5,933.4
Cost of sales	4,905.7	4,332.5
Selling, general and administrative expense	665.9	585.9
Gain on sale of assets	0.0	(14.0)
Other (income) expense	(15.5)	(5.3)
Income before income taxes	1,497.3	1,034.3
Income tax expense	351.5	239.1
Net income	1,145.8	795.2
Net income attributable to noncontrolling interests	4.2	3.4
Net income attributable to D.R. Horton, Inc.	$ 1,141.6	$ 791.8
Basic net income per common share attributable to D.R. Horton, Inc. (in dollars per share)	$ 3.21	$ 2.17
Weighted average number of common shares	356.1	364.4
Diluted net income per common share attributable to D.R. Horton, Inc. (in dollars per share)	$ 3.17	$ 2.14
Adjusted weighted average number of common shares	360.1	370.0